... Fatigue is another side effect I have developed since taking the drug. I hate to go off it since it is working. It is about the only non PPI drug that works for me. I have been on cimiditine for about 2 weeks. I take one 300 mg tab a day. I thought about splitting it and seeing if that helps. The only other meds I take are a water pill and atenenol. Half a tablet each, so not much is taken. I do take Floraster, a probiotic.